Guides
Basic, broad and special causes of loss forms: what each covers
ISO's three causes of loss forms decide which perils your property policy pays for. Compare CP 10 10, CP 10 20 and CP 10 30 and see where claims diverge.
ISO's commercial property program splits a policy into two pieces: a coverage form that says what property is insured, and a causes of loss form that says which events it is insured against. There are three causes of loss forms. Basic (CP 10 10) and Broad (CP 10 20) are named-perils forms that pay only for the events they list. Special (CP 10 30) is an open-perils form that pays for direct physical loss unless the loss is excluded or limited. Most buyers should have Special, and many leases and loan agreements require it.
The ISO building and personal property form, CP 00 10, does not list perils at all. For Covered Causes of Loss it points to the causes of loss form shown in the declarations. Policy language varies, and carriers amend these forms, so read the one attached to your policy and check its edition date.
How the three forms differ
Basic (CP 10 10) | Broad (CP 10 20) | Special (CP 10 30) | |
|---|---|---|---|
| Approach | Named perils | Named perils | Open perils |
| Core perils | Fire, lightning, explosion, windstorm or hail, smoke, aircraft or vehicles, riot or civil commotion, vandalism, sprinkler leakage, sinkhole collapse, volcanic action | Everything in Basic | Any direct physical loss not excluded or limited |
| Adds | Falling objects, weight of snow, ice or sleet, water damage | Theft and other causes the named lists leave out, subject to exclusions | |
| Who proves what | Insured shows a named peril caused the loss | Same | Insurer shows an exclusion applies; insured shows any exception |
The Basic list is the eleven perils IRMI lists for 0, and the Broad additions come from IRMI's description of the broad form, which also counts collapse from specified causes among them. On who proves what, courts treat the burden as sitting with the insured under a named-perils form and with the insurer, on exclusions, under an open-perils form, though the rule varies by state.
What the named perils really cover
Each named peril comes with qualifiers, and the qualifiers produce most of the disputes. As the ISO forms word them:
- Windstorm or hail does not extend to damage to the inside of a building from rain, snow, sand or dust, unless wind or hail first damages the roof or walls through which it enters. The special form carries the same limitation.
- Vehicles means physical contact of a vehicle with the property, and the Basic and Broad forms do not pay for vehicles you own or operate.
- Vandalism is willful and malicious damage. Theft is not covered, apart from damage to the building by burglars breaking in or leaving.
- Falling objects (Broad and Special) excludes personal property in the open and the inside of a building unless the roof or an outside wall is first damaged by the falling object. The special form's definition says so.
- Water damage (Broad and Special) means the accidental discharge or leakage of water or steam from a plumbing, heating, air conditioning or similar system, and does not include flood, surface water or sewer backup. The 09 17 edition of the special form also reaches water escaping from a broken off-premises water or sewer pipe operated by a utility under certain conditions, as IA Magazine reported in October 2017.
How the Special form is built
The CP 10 30 (09 17 edition) structure matters because it is where coverage is lost or restored. The form is organized as follows:
- Covered Causes of Loss. Direct physical loss unless the loss is excluded or limited in the policy.
- Exclusions. The form groups them: those that apply regardless of other causes (ordinance or law, earth movement, governmental action, nuclear hazard, utility services, war, water, and fungus and rot); those that apply to loss caused by or resulting from the listed cause (wear and tear, rust, latent defect, mechanical breakdown, electrical arcing, continuous seepage over 14 days or more, dishonest acts, collapse and others); and a third group with ensuing-loss exceptions (weather conditions that combine with a first-group cause, acts or decisions of others, and faulty design, workmanship or maintenance). commercial property exclusions: what the standard policy won't pay covers each and anti-concurrent causation clauses: when one excluded cause sinks a claim covers the first group.
- Limitations. Property restricted to the "specified causes of loss" or building glass breakage, special theft limits, and rain or snow damage inside a building.
- Additional coverages. Collapse, and a limited coverage for fungus, wet rot, dry rot and bacteria capped at $15,000 for a 12-month period under the form.
- Extensions. Property in transit up to $5,000, tear-out costs to repair a system that leaks, and glass (temporary boarding and removing obstructions).
The "specified causes of loss" definition is the Special form's list of named events, and it tracks the Broad form closely: fire; lightning; explosion; windstorm or hail; smoke; aircraft or vehicles; riot or civil commotion; vandalism; leakage from fire-extinguishing equipment; sinkhole collapse; volcanic action; falling objects; weight of snow, ice or sleet; and water damage. The form uses that list to limit animals, fragile articles (but not glass) and builders' machinery, and to give back coverage when an excluded cause leads to one of those events.
Special does not mean everything. The form's own special limits for theft are $2,500 for furs, $2,500 for jewelry and watches (with exceptions), $2,500 for patterns, dies, molds and forms, and $250 for stamps and tickets, unless the declarations show a higher limit. Property that is missing with no physical evidence of what happened is excluded. So is voluntary parting with property induced by a fraudulent scheme, and property transferred to a person or place outside the premises on unauthorized instructions.
The same loss under all three forms
The table assumes standard ISO wording with no endorsements, and the facts are hypothetical.
| Loss | Basic | Broad | Special |
|---|---|---|---|
| Wind tears a section of the roof and rain soaks stock | Covered | Covered | Covered |
| A vandal smashes the storefront glass | Covered | Covered | Covered |
| A tree limb falls on the roof in calm weather | Not covered | Covered | Covered |
| A pipe inside a wall bursts suddenly | Not covered | Covered | Covered (the water damage, not the pipe repair) |
| Weight of heavy snow damages the roof | Not covered | Covered | Covered |
| Burglars carry off inventory | Not covered | Not covered | Covered, subject to limits and exclusions |
| Your own employee steals inventory | Not covered | Not covered | Not covered (dishonest acts exclusion) |
| Rising water floods the sales floor | Not covered | Not covered | Not covered (water exclusion) |
The bottom rows show the gap that surprises people: theft. A business that expects a property policy to cover break-ins and has a Basic or Broad form, or a Special form with a low theft limit, may have no theft coverage worth the name. commercial crime insurance: what it covers and what it excludes covers employee theft, money and securities, which no causes of loss form picks up.
Causes of loss no form covers
None of the three covers flood, earthquake, sewer backup, off-premises utility failure or the extra cost of building to current code by default. These are restored by endorsement or by a separate policy:
- Flood and surface water: the NFIP, a private flood policy, or an endorsement; see Commercial flood insurance: NFIP limits and private options.
- Earthquake: the ISO earthquake endorsement
CP 10 40or a standalone policy; see earthquake insurance for businesses: coverage, deductibles, limits. - Off-premises power and water: a utility services endorsement; see utility service interruption coverage: when an outage is insured.
- Code upgrades: ordinance or law coverage: paying for code upgrades after a loss.
- Large flood and quake limits for a high-value location: a DIC policy.
Endorsements can also take coverage away. A windstorm or hail exclusion (CP 10 54) can be attached to property in exposed areas, and carriers may instead apply a separate wind or hail deductible. The named storm deductibles: how percentage wind deductibles work guide covers that.
What leases and lenders ask for
Contracts tend to name Special. The New York State Office of General Services lease boilerplate dated July 7, 2026, for example, requires the landlord to insure the demised premises for not less than full insurable value, covering at a minimum the perils of the ISO Special Causes of Loss Form CP 10 30 or the equivalent, including ordinance or law coverage to the extent commercially available (OGS lease template). Commercial leases and loan agreements commonly use similar wording. See insurance requirements in commercial leases.
Basic and Broad forms still turn up where coverage is deliberately narrow: some vacant-building policies and high-hazard risks are written on a named-perils basis. vacant building insurance and the vacancy clause shows how the vacancy conditions work.
How to check your own policy
- Find the Causes of Loss column in the declarations. It may say Basic, Broad or Special, and it may differ by building, contents or business income.
- Read the form number and edition date at the bottom of the causes of loss form, and check that any endorsements amending it are listed.
- Compare the list of exclusions against the risks in your building. Flood, quake and utility failure are the usual ones.
- Ask your broker for the theft limit and how it works with a sublimit on the declarations.
- Ask whether any endorsement changes the wind or hail coverage, deductible or valuation.
- Match the answers to what your lease or loan agreement requires.
Key takeaways
- Basic (
CP 10 10) and Broad (CP 10 20) pay only for named perils, while Special (CP 10 30) pays for any direct physical loss that is not excluded or limited. - Broad adds falling objects, weight of snow, ice or sleet, and water damage to Basic's eleven perils. Special adds theft and everything else not excluded.
- Special has its own exclusions, limitations and sublimits: flood, earthquake, utility failure, fungus and ordinance or law are the big ones, and theft limits are low.
- Leases and lenders commonly require Special, and some set the standard in writing.
- Check the declarations for the form, the edition and the endorsements, and buy the missing perils separately.